Technical Specification Proposal for Use of High-Performance Recycled Concrete Aggregates in High-Performance Concrete Production

Abstract

The need to reduce the world’s ecological footprint has encouraged the construction sector to look for more innovative solutions to reuse its waste production. Since concrete waste is one of the biggest waste streams in the sector and in the world, reusing it would largely contribute to solve this problem. Various strategies have been followed and this kind of waste has been mostly used in road pavements activities. However, it has been proved that it is possible to use this waste for current concrete structural elements. This investigation proved that it is also possible to produce high-performance concrete made of both fine and coarse recycled concrete aggregates. It was even possible to produce a type of high-performance concrete made with total replacement of natural aggregates. However, present legislation, in the world in general and in Portugal in particular, does not allow this level of replacement ratio, particularly for fine recycled aggregates. In fact, most of the legislation around the world do not allow to use fine recycled aggregates in high-performance concrete. In this work, a simple specification proposal is presented to incorporate both fine and coarse aggregates to produce high-performance concrete. It was the result of a wide experimental campaign constituted of 3,49 laboratory tests. This specification defines the types of cement mix and the maximum replacement ratios that should be respected to produce five classes of high-performance concrete.